You're right, but you have to remember that the TOPS-20 we remember was
much, much nicer than the TOPS-20 we actually used...

(Oh, and I'd have to add the TOPS-20 still is extremely nice, by any
standard.)
And line editing is much less needed when you have all the nice command
completion in there. Don't hurt as much to delete a few words (with ^W)
to correct something when it's so easy to re-input the stuff you deleted.